Telephone system



A. S. HIBBAR-D. TELEPHONE SYSTEM.

2 she ets -sheet 2.

(No Model.)

Patented July 2, 1895.

ji /varzfif JryMJJ/ZZZA r/ZZ UNITED ST TES PATENT I OFFICE.

ANGUS S. I-IIBBARD, OF CHICAGO, ILLINOIS.

TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters PatentNo. 542,052, dated July 2, 1895.

r I Application filed February 21, 1895- Serial No. 539,188- (No model.) i

.Im provement in Telephone Systems, (Case No.

5,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to a telephone system, my object being, in general, to facilitate the making of connections between the subscribers and to lessen the time required in making such connections.

In accordance with my invention the tele' phonelines of the subscribers extendto divided boards at the central stationthat is,

t. the lines of a group of subscribers, say three hundred, will terminate upon one board at the central station, while another group of subscribers lines'will terminate upon a second board, and so on, the subscribers being thus divided into groups, the linesnof each group terminating upon a separate board. An operator'is stationed at each of the divided boards to answer the calls of the subscribers whose lines terminate at a particular board,

and these operators I. designate for convenators being connected with the boards of the B operators by local trunk-lines. In the preferred form of my invention I provide at each of the divided boards a series of local-trunkline plugs, say twelve in number, the local trunk-lines being extended to the board of an A operator, where they terminate in connecting-plugs. Likewise at each of the divided boards a series of plugs is provided, connected through local trunk-lines with a second A operator, a third set of pings being connected with a third operator, and so on, as many A operators being thus connected with each of the divided boards as may be found necessary in handling the connections.

WVhen a call is received at one of the divided boards, the B operator stationed thereat inserts one of the local-trunk-line plugs into the spring-jack of the calling subscriber, thus extending the line of the calling subscriber to the plug of the particular A operator chosen. The A operator chosen will be determined by the number of connections that she may already have under control, as will be evidenced by the number of idle plugs at the divided board which belong to her set. The B operator is thus enabled to distribute the work at will amongthe several A operators.

In the arrangement of the spring-jacks and individualannunciators at the several divided boards I preferably arrangethe indicators in the form of small incandescent lamps situated just above the spring-jack, the lamps being lighted when the subscriber removes his telephone from the hook to thereby convey the signal for connection to the B operator. The B operator, without listening in, merely inserts one of the local-trunk-line plugs into the spring-jack indicated by the lighting of the lamp, thus extending the connection to an A operator, who bridges her telephone into circuit and receives the number of the called subscriber and completes the connection.

At each of the divided boards is provided a series of plugs connected with incoming local'trunk-lines, the local trunk-lines being extended to spring-jacks multiplied upon the boards of the A operators. The A operator, having received the number of the called subscriber, places herself in communication by means of an order-Wire with the B operator stationed at the board at which the line of the called subscriber terminates and inquires of her as to which of the incoming trunk-lines she may employ in completing the connection. Being informed, she inserts the plug over which the line of the calling subscriber has been extended into the spring-jack: of the incoming trunk-line, and the B operator at the board of the called subscriber inserts the! plug of the particular incoming line chosen into the spring-jack of the called subscriber, the connection between the calling and the called subscriber being thus completed.

In connection with each of the'ontgoing local trunk-lines-that is, thelines extending from plugs at the divided boards to plugs at the intermediate boards or plugs of the Aoperatorsis provided an indicator, adapted to be actuated when the B operator at the board 'sition of the repeating-coil.

of the calling subscriber inserts the locali trunk-line plug into the spring-jack of the calling subscriber, the attention of the Aoperator being thus called to the fact that a connection is desired through the trunk-line to which theparticularindicator'belongs. The lampof the calling subscriber remains lighted until the A operator, having received the number of the called subscriber, lifts the local-trunkline plug fromits socket for the purpose of extending the circuit. The lifting of the plug from its socket opens the lamp-circuit, thus extinguishing the lamp and informing the B operator that the A operator has responded and is attending to the call. in the circuit of the outgoing local trunk-line is inserted a repeating-coil, and between the opposite sides of the repeating-coil and ground are provided indicators adapted to be actuated by the connected subscribers, the indicator being individual to the subscribers, due to the interpo- The subscribers may thus send in clearing-out signals independently, the A operator being the one who receives the signals for disconnection. Upon the removal of the outgoing-trunk-line plug from the spring-jack of the incoming-trunkline circuit connections are operated which serve to close circuit through the lamp of the called subscriber, thus informing the B operator at that board that a disconnection is desired. The replacement of the plug in its socket serves to close circuit through the lamp of the calling subscriber, thus informing the B operator at that board that adisconnection is desired. The B operator, noting the signals for disconnection,removesthe trunk-lineplug from the spring-jack.

I will describe my invention more in detail, with reference to the accompanying drawings, in which Figure 1 illustrates, diagrammatically, two subscribers lines and the intermediate trunklines for connecting the two lines for conversation. Fig. 2 represents a modification of the A operators apparatus.

Like letters refer to like parts throughout both figures.

The line of subscriber A extends in two limbs a a to the central station, where the limbs terminate in line-springs a a respectively. The line-spring a normally rests against a contact a connected to ground, while the line-spring a normally rests against the contact a extending through the coil b of a relay and a battery I) to ground. 'A lamp 1) and source of current b are included in a local circuit adapted to be closed by the armature b of the relay when the coil is energized. When the telephone'rcceiver a. of the subscriber rests upon the hook ad, the limb a is grounded through a hell or call device a The removal of the telephone-receiver from the hook disconnects the limb a from ground and closes together the twolimbsaa' through the telephone receiver and transmitter.

The line of the subscriber B extends in two limbs c c to line-springs c 0 resting, respect:

ively, upon contacts 0 0 connected to ground, the former through the relay-coil d and battery'd', a lamp d and battery cl being included in the local circuit of the relay, which is adapted to be closed by the armature d At the board at which the line of thesubscriber A terminates is provided a plug e, the tip and sleeve-strands e e of which extend to the opposite ends of the windingf of the repeating-coilf. The ends of the winding f are connected by strands e e with the collar g and sleeve 9 respectively, of the plug g. The plug g normally rests in a socket 9 with which the collar g makes electrical contact, the socket 9 being connected by a strand 6 with a collar 6 provided on the plug 9, the collar e being adapted to make contact with a ring a", provided upon the subscribers spring-jack, the ring a being electrically connected with one side of the battery I). From the middle of the winding fof the repeating coil a circuit extends to ground through an indicator h and a battery h, the connection being preferably made at the middle of the winding f to balance the line. Likewise from the middle of the winding f a circuit extends to ground through the indicator 7c and battery 7c. A ringing-circuit extends from the strand e through a conductor Z, normally-open contact-points Z Z and generator Z to ground, the contact-point Z being carried upon a pivoted lever m, adapted to be raised by the depression of a key m, the lever m, which is made of magnetic material, being thus brought within the field of the electromagnet of indicatork and maintained in this position so long as current passes through the indicator It. The lever m carries a target m which is brought into view when the lever is raised. At the board at which the line of subscriber B terminates I have illustrated a plug n, the tip 'n' and sleeve n of which are connected by the limbs n 'n of a local trunkline with spring-jacks 0 0', multiplied at the boards of the severalA operators, the limb n being connected with a line-spring o of eao ICT ground, the insertion of a plug in the spring board of the called subscriber extend the limbsp p of an order-wire, the operators being provided with head -telephones p and transmitters p The A operator is provided with a listening-key 7", by means of which she may bridge her telephone into circuit with the calling subscriber, and with a series of orderwire buttons '8, by means of, which she may whom she desires to converse.

In the drawings I have illustrated butone order-wire, but it will be understood that a number of order-wires are provided extending from the A operators board to the boards of all the B operators with whom itwill be necessary to converse. Likewisel have shown but one outgoing trunk-line extending between the board of the calling subscriber and the A operator; but in practice a number of such trunk-linessay twelve in numberis provided. Likewise a number of incoming trunk-lines are provided between the board of the called subscriber and that of the A operator. W'hen the lines of the calling and the called subscribers terminate at the same board, the B operator thereat will insert the plugs of both the outgoing and the incoming trunk-lines.

I will now describe the operation of connecting two subscribersfor conversation.

posing that subscriber A wishes to converse with subscriber B he removes his telephone from its hook, thus completing the circuit of tion.

the battery b through coil 1) of the relay, contact aispring a limbs a a of the telephone line, spring a, contact a to ground and back to opposite side of the battery. The circuit of battery 11 through. lamp b is thus closed and the lamp is lighted, indicating to the B operator that subscriber A desires .a connec- The B operator, having decided which of the A operators lines she will choose for extending the circuit, inserts plug 6 into the I spring-jack of the called subscriber. closes the circuit of battery through coil b. tithe relay, ring a", collar e ot'the plug,strand socket g to the metallic butt-piece of the alugg, which is connected to strand e thence ,through half of winding f through the coil ;of indicatork, battery It to ground. The light 1 2 thus remains lighted and the indicator is t actuated to convey to the A operator inmation that aconnection is desired through the trunk-line to which said indicator belongs. The'A operatorwthen takes up the plug indicated by the signal, thus indicating to the B operator that the call is received,

i' 'ilepresses key 1", bridging in her telephoneset, and inquires the number of the called subscriber. The A toperator then presses the order-wire button, thus. connecting her telephone-set in circuit with the telephoneset of the B'operator at the board of the called 4 subscriber B and inquires as to which trunktion.

number and the A operator inserts the plug line she shall employ in making the connec- The B operator indicates the line by g'into the spring-jack of that line. The removal of the plug g from the socket g opens the circuit of battery I), thus extinguishing lamp b and indicating to the B operator at the board of the calling subscriber that the This .called subscriber. The A operator then sends a ringing-current through the bell of subscriberB by depressing the key m, the circuit of generator Z being thus closed through contact Z Z, conductor Z, sleeve 9, spring 0 limb n of trunk-line, tip at, spring 0 limb c, and the bell of subscriber B to ground. The depression of key m raises lever m, thus displaying target m the ringing-circuit being thus maintained closed by the attraction of lever m by the magnetic field of indicator it. During this time the current of battery is closed through indicator It, strand e sleeve 9 limb n of trunk-line, limb c of the telephone-line, and through bellof subscriber B to ground, the coil of indicator It being thus energized until the subscriber B removes his telephone from the hook, which opens the cir cuit of. battery'k', de-energizing the coil of indicator is and permitting the targets m and 70 to fall to indicate that subscriber B has responded. Subscribers A and B are thus in conversation. g

The indicator 7.0 is exclusively under the control of'subscriber B and may be actuated by replacing his telephone upon thehook.

Likewise the indicator It may be controlled by actuating the clearing-out annunciators h and 7t and informing the A operator that they desire disconnection. The A operator then re moves plug 9 from the spring-jack 0 and replaces it in the socket The removal of the plug g from spring-jack 0 permits the springs a to come in contact with contact 0, thus closing circuit from ground through contact 0 spring 0 contact 0, spring 0 strand n collar 01, of the plug '21, ring 0 relay (1, and battery d to ground. The relay d is thus actuated to close the local circuit through lamp d thus informing the B operator that a dis connection is desired, whereupon the B operator removes the plug n from the spring-jack of the called subscriber, The replacement of the plug g in its socket g closes circuit from battery I) through relay 1), ring a", collar 6 of plug 6, strand e socket g to the metallic buttits piece of plug g, strand 6?, socket g to the coil f indicatork, battery It to ground. The cirthe board of the calling subscriber that the plug e is to be withdrawn from the springjack of the calling subscriber.

While the generator Z is connected in circuit for sending a ringing-current through the called subscribers bell a derived current passes through strand a, half of Windingf of the repeating-coil, indicator 7c, and-battery k to ground, current thus traversing the repeating-coil to cause a buzz in the telephone of the calling subscriber to notify him that the call has been'sent to the called subscriber. Upon the cessation of the buzz the calling subscriber will know that the called subscriber has removed his telephone from its hook.

In Fig. 2 I have illustrated a modification of the A operators apparatus. The apparatus upon the side of the repeating coilf toward the calling subscriber is substantially that illustrated in Fig. 1, but the indicator adapted to be controlled by the called subscriber is somewhat differently connected. The'windingj of the repeating-coil is made in two sections f f connected respectively to the opposite strands e e, one of the sectionsf being connected through a relay t and battery 74: to ground. In the local circuit of the relay is included a battery 15 and indicator k. The end of the section f of the repeating-coil is connected with the spring c of a switch, said spring being normally closed against a contact o, connected with the section f of the repeating-coil. The spring t when moved out of contact with contact 0 by the depression of key m engages a contact 11 which is connected to ground through a calling-generator F. The armature of the indicator carries a hook 70 adapted to engage the end of key m when depressed and hold the same in its depressed position until the indicator is actuated, whereupon the key is released. While the key is held depressed generator Z is closed in circuit. In circuit with the generator Z I provide a rotating commutator to, having two segments to 10 upon which bears a brush w One segment to is connected with the generator, while the other to is connected to the ground by a shunt-circuit w During a part of the time the generator is in circuit and during the rest of the time the generator is on open circuit; but the circuit from the contact '0 is completed to ground through the shunt 10 A path to ground for the current from battery 7c is thus afforded without the necessity of passing through the conductor containing the generator Z 7 When the B operator at the board of the calling subscriber inserts plug 6, circuit is closed through strand 6*, relay t, and battery it, thus actuating indicator 7c and calling the attention of the A operator. In ringing, the

key m is depressed, thus closing the generator l in circuit through contact 0 and spring o and the section f of the repeating-coilf to the strand e and through the bell of the called subscriber to ground. The hook 70 engages the key m and maintains. the same depressed until the called subscriber removes his telephone from his hook, when the indicator is is actuated to release the key m and permit the spring 1; to break contact with contact o circuit being closed upon the removal of the called subscribers telephone from its hook from ground through battery It, relay 15, section f of the repeating-coil, strand 6 through the telephone of the called subscriber and back to strand 6 through section f of the repeating-coil, spring 11, contact 11 to ground through the shunt-circuit w upon each revolution of the commutator w. Since, in ringing,-the current from the generator Z passes through the section f of the repeating-coil, the called subscriber will hear a buzz in her telephone, thus informing her that the called subscriber has been called, and upon the cessation of the buzz will know that the called subscriber has removed his telephone.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is V 1. The combination with telephone lines extending in groups to divided boards of an exchange, of two or more intermediate boards, trunk lines extending between the divided boards and the several intermediate boards adapted to be connected with the telephone lines to extend the circuits at will to any one of the intermediate boards, and means at the intermediate boards for uniting two trunk lines; whereby the connection between any two lines may be completed through any one of said intermediate boards at will.

2. The combination with a telephone line, terminating upon a divided board of the exchange, of an intermediate board, a trunk line extending between said divided board and said intermediate board and adapted to be terminating upon a divided board of the ex- 7 change, of an intermediate board, a trunk line extending between said divided board and said intermediate board, and adapted to be connected with said telephone line to extend the circuit to the intermediate board, a telephone line terminating upon a second divided board, a trunk line extending between said second divided board and said intermediate board and adapted to be connected with said telephone line to extend the circuit to the intermediate board, means at the intermediate board for uniting the two trunk lines, signal- 1 ing apparatus at the intermediate board controlled by the subscribers whose lines are connected together, and signaling apparatus at e the divided boards adapted to be actuated by the disconnection of the trunk lines at the intermediate board, substantially as described. 4. In a telephone system, the combination with a telephone line terminating upon a divided board of an exchange, of an intermedii te board, a trunk line adapted to be connected with said telephone line to extend the circuit to the intermediate board, said trunk line terminating in a plug at the intermediate ,3 hi ard normally resting in a socket, a second telephone line terminating upon a divided bc ard, a trunk line adapted to be connected with said telephone line to extend the circuit to the intermediate board, said trunk line termi nating in a switch at the intermediate board into which the plug of the first trunk line is pted to be inserted to complete the con- 11E( tion, signaling apparatus at the divided boa rds, means for actuating the signaling appar atus at one of said boards by the removal of said'trunk line plug from the trunk line swi told, and means for actuating the signaling ap aratus at the second board by the replacingof the plug in its socket, substantially as d scribed.

5. The combination with a telephoneline exi-line extending from a plug at said board to a ping at an intermediate board, a repeating cator in a ground branch from the trunk on the side of the repeating coil toward the plug at the intermediate board, a socket in which said plug normally rests to make electrical connection between said trunk line and said socket, a third wire extending from said socket to a contact terminal on the plug at the board at which the telephone line terminates, said terminal adapted when the plug is inserted in the switch of the telephone line to complete the circuit of a battery through said indicator to call the attention of the operator at the intermediate board.

6. In a telephone system, the combination with a repeating coil interposed between the 1,0 calling and the called subscriber, of a generator adapted to be connected in circuit with tending to a board of the exchange, of a trunkcoil interposed between the plugs, an indithe called subscriber, and a key for throwing said generator into circuit adapted when dopressed to connect one coil of said repeating coil in series with the generator, whereby a buzz in the telephone of the calling subscriber is produced, substantially as described.

7. In a telephone system, the combination with means for connecting the two telephone lines together, of a battery and a calling generator adapted to be connected in circuit, and a commutator for intermittently opening the circuit of the generator and closing a shunt about the same to afford a path for the battery current, substantially as described.

8. In a telephone system, the combination with two telephone lines connected together, of a repeating coil interposed between the telephone lines, a key adapted when depressed to include a calling generator in circuit and simultaneously open the repeating coil circuit, and an electromagnet adapted to maintain said key depressed until the called subscriber removes his telephone from its hook, substantially as described.

9. The combination withatelephonelineextending to the board of an exchange, ofan indicator at said board adapted to respond to callingcurrents sent from the sub-station, a trunk line adapted to be connected with the line to extend the circuit to a switching board, and means controlled by the change of said trunk line from a position of use to a position of disuse for operating said indicator to convey a signal to disconnect the trunk line, substantially as indicated.

10. The combination with telephone lines extending in groups to divided boards, of call receiving indicators therefor at said divided boards adapted to be actuated from the substations, two or more intermediate boards, and means for extending the line of a calling subscriber atwill from the divided board to the particular intermediate board that may be selected for answering the call, substantially as described.

Inwitness whereof I hereunto subscribe my name this 9th day of February, A. D. 1895.

ANGUS S. HIBBARD.

Witnesses:

GEO. S. IREDELL, W. CLYDE J ONES. 

